a) people can change whether low rated posts are hidden or not in the settings page
b) if a post gets downvoted by different members, there must have been a reason
These constant complaints are fueled by people who feel that their opinions and posts must be seen by everyone. But if they say something other posters don't feel adds value to the discussion, it might be downvoted. That is how the system is intended to function.
Let me ask you this, were you always this upset about downvoting, or just recently because of the couple people who have brought it up?
I've seen a lot of people get downvoted on occasion, but they didn't make a big deal out of it. I doubt how concerned you are about the forum's integrity. Seems to be a little more personal, but I could be wrong. Then again you're assuming people don't know the forum as well as you. Seems a bit arrogant, but whatever.